Refrigerating cabinet



Oct. 19 1926.

C. E. L. LIPMAN REFRIGERATING CABINET 2 Shets-Sheet 1 Filed Jan. 16. 1924 Oct. 19 1926.

C E. L. LIPMAN REFRIGERATING CABINET Filed Jan. 16 1924 2 Sheets-Sheet 2 a, la lare..

. 1L. Mirti a Stimm,

MFMQTM@ SUMMER .application tiled January Ml, 1921i. aerial Elo. tiental.

This invention pertains to storage cabinets in which loodstuds such as ice cream, tor instance, are stored and maintained at a desired low temperature.

lPrior to my invention it has been the cus tom to provide cabinets tor the purpose indicated which vvere constructed to provide a brine tanlr into Which the lood containers project. llel'rigerating coils connect/ed to a suitable refrigeratin g machine were disposed vvithin the tank and the retrigerating edect ci these coils was exerted upon .the lood containers through the intermediary ci the surronnding brine which customarily was circulated by a suitable pump to maintain a uniformity ol temperature within the tank and around the various containers. Such brine containing cabinets, however, possess many disadvantages among vvhich may be mentioned the tact that the cabinet itself nas necemarily very heavily constructed in order to hold a large quantity ot this heavy brine, the interior vvalls ol the cabinet Were subject to the corrosive edect ot the contained brinebvvhich sooner or later resulted in lealrage ot the brine from the cabinet, the employment ol a brine circulating pump increased not only the manufacturing and installation costs, but also the cost ol operation, and in addition the initial charging and the subsequent replacement of the tanlr with brine added to the labor and expense ot maintaining the cabinet in practical operation.

@ne ot the primary purposes ot my present invention is 'to eliminate all ot the atonementioned and other objections to the use ot brine cooled cabinets by entirely eliminating the brine, the circulating pump and the other expensive features necessitated bythe use ot brine, and with this end'in view my invention contemplates the provisions ot a cab inet which is cooled by direct expansion in the cooling coils, the heat units being translerred trom the lood containers to the coils by conduction and convectional action ot the air in the cooling chamber surrounding the lood containers. i

Another purpose ot the invention is to distribute the retrigerating edect ofthe expansion coils with `respect to the toed containers so that the containers may be maintained at l the desired temperature trom top to bott/om.

ln order to secure this result the coils are so arranged and disposed relatively to the containers that their retrigerating elilect is distributed, and having in mind at the same time the convectional action ot the air surrounding the coils and the containers, the ultimate result is the maintenance ol' the containers at the desired temperature.

ln order to facilitate an understanding ot my invention l have illustrated on the accompanying drawings a preferred embodiment thereof.

Referring to the drawings:

Fig. l is a plan vievv partially in section ot a cabinet embodying my invention; and

Fig. 2 is a sectional vievv on the line 2--2 of Fig. l.

Referring now to the drawings more in detail, it will be observed that the cabinet proper comprises side Walls 3, bottom Ll,vend walls 5, and a top 6, all comprising in their construction heat insulating material so as to provide a heat insulated chamber in which the food containers are disposed. llVhile the structure ot the Walls of the cabinet may be Widely varied, they preferably comprise a metal outer Wall 7., lined With corlrboard, or other suitable heat insulating material 8, over the inner surface ol which is laid a layer ot asphalt 9, the whole construction being lined with a metal lining ll.

il plurality of open-top lood containers are disposed Within the chamber thus formed, sin ot such containers bein shown in the present drawing lor illustrative purposesy and indicated by reference characters l2, i3, lll, l5, 16 and i7, respectively.. Each ot' the containers is preferably termed oty (dll lll

metal andthe interior thereof is sealed against communication vvith the surrounding cooling chamber by a suitable seming sleeve i8. l removable cover i9 also termed ot heat insulating material is adapted tri close the top ot each container. y

'l'he retrigerating vvorh pertormed uponthe containers may be reduced by any sintable retrigerating mac e, and inthe pres ent instance ll have shown :tor illustrative purposes merely a conventional machine which is indicated generally by reference character-2l, the machine being ol the compression type vand having a. regulatabh er:- pansion valve 22 interposed in the expansion ipe 23 ot the circuit, the suction pipe 2d,` lleading trom the expansion coils, being connected with the intake side ol the compressor in the 'usual manner. This retrigerating map cliine may be mounted in any convenient location remote from or in proximity to the cooling chamber, but for convenience it is preferably installed in a compartment provided at one end of the cooling chamber as shown in the-idrawings, particularly Fig. 2 thereof.

The cooling chamber in which the containers are disposed isfor `all practical purposes hermetically `sealed and the space within the chamber surrounding the containers is filled with air only, no liquid refrigerating medium such as brine or other solutions pjossessing the undesirable characteristics a ove enumerated being employed. The expansion coils of the refrigerating system which serve as the cooling coils for the containers are disposed in this `chamber around the containers, and while these coils are not in contact with the containers, the arrangement of the coils in the substantially hermetically sealed chamber, together with A the conduction and convectional properties of the air in the chamber, serve to cool othe containers and maintain them at the desired temperature. The refrgerative work exerted byithe coils may of course be regulated by controlling the o ration of the refrigerating machine an preferably the cooling chamber is provided with a thermostat equipped to automatically control themachine so as to. maintain a redetermined temperature within the chamber. t

The pipe 23 leading from the expansion valve 22 connects inside the coolin chamv y ber with the first convolution 25 of t e cooling coil.l The coil is arranged in convolutions around the containers as illustrated in Fig. 1, the first convolution being at the top of the coil. Instead, however, of winding the coil entirely from top to bottom, I found that a greater uniformity of tem erature of the containers may be maintaine b windmg the coil from the top downwardly for a portion" of the heigit of the containers, whereupon the cpipe om which the coil is formed is exten ed downwardly as indicated at 26 (Flg. 2) tothe bottom of the chamber. From this-point the coil is then wound in upwardly extending convolutions until ity meets the previously wound downwardly extending convolutions, whereupon the pipe is extended directly upwardly as indicated at 27, its u r end being returned through the end wal ofthe chamber and connected with the suction pipe 24.

Itwill be wen that I have provided a rei frigerating cabinet from which all brine or other solutions are eliminated. The cabinet can therefore be manufactured more economically than a brine tank type. i The brineitself and the circulating pumpsY are dispensed with, ythus resulting in a lighter, cheaper, and more sanitary cabinet than the brine cabinets heretofore employed. The eX- reoaaaa pension coils oi the reirigerative system are disposed directly in a closed cooling chamber in which the food containers are disposed; the containers and the expansion coils are surrounded by air only which is capable of heat extraction from the containers by direct conduction to a limited extent. This heat transference by conduction is urther'augmented, however, by the convectional action of the air produced by diiferentials of temperature between the coils and the exterior walls of the containers. Currents are set up which rapidly transfer the heat 'units from the containers to the coils from which the units are removed by the circulating refrigerating medium therein. By winding the coils from the top downwardly for a predetermined distance the greatest cooling ei'ect is produced first near the top of the containers. In the present case, if the coils were wound continuously from the'top to the bottom of the containers, a ,certain amount of the refrigerating vapor would, when the machine 1s intermittently stopped, condense in the tubes and repose in the lowermost coils of the winding.r When the refrigerating machine 21 commenced to operate again, a certainv amount of the liquid might be drawn upward through the pipe 27 as a slug of liquid 95 into the compressor with very injurious results thereto. In any event, even if liquid was not drawn upward through the return pipe 27, a vacuum would be created in said pipe upon the operation of the machine 21, and the vaporized rerigerant would only tend to reduce the temperature in the region of said pipe and not in the lower coils around the containers.

By winding the coils in the manner shown tot and described in this application, the condensed rerigerating vapor will lie in the lowermost coil and when the machine 2l is started, a vacuum will be created inthe pipe 27 whichv will vaporize the condensed reu@ frigerant and perform refri erating work in the successive coils, there y decreasing the temperature around the lower part of the containers. This method of winding will therefore tend toward uniformity of temim perature of lthe containers throughout their epth and also preclude injury to the compressor, as the refrigerant which has been condensed in the coils will be returned to the compressor in vapor form. y

I have discovered that the best results are accomplished when the downward winding is continued throughout a portion of the height of the containers, whereupon the pipe is extended-to the bottom of the chamber uw and then wound upwardly for a limited distance. This winding of the coil in two directions about the containers not only tends toward uniformity of temperature of the containers throughout their depthV m mi direct conduction, but is also conducive toward and facilitates .the desired convectional air currents established in the chamber. A high degree of eiiciency is accordingly secured which enables the maintenance of the containers at a desired refrigerated temperature in a dry, sanitary cabinet which is extremely economical to manufacture, install and operate. The structural details illustrated and described may obviously be varied within considerable limits without exceeding the scope of the invention as deiined in the following claims.

ll claim:

l. A refrigerating cabinet comprising a closed air filled chamber, an open-top container extending into said chamber, and an expansion coil of a refrigerating system surrounding said container within the chamber, said coil being wound from the top of the container downwardly throughout a portion of its length and then wound from the bottom of the container upwardly throughout the remainder of its length.

2. A refrigerating cabinet comprising a chamber having heat insulating Walls, a

plurality of containers extending into said chamber and accessible from outside the cabinet, and a direct expansion cooling coil arranged within said chamber around said containers and spacedthererom, said coil being wound downwardly throughout a portion of its length and upwardly throughout the remainder of its length.

3. A refrigerating cabinet comprising a cooling chamber having heat insulating walls, a plurality of open-top containers extending downwardly into said chamber, said chamber being substantially hermetically sealed around said containers, anda direct expansion cooling coil disposed within sald chamber around the containers, said coil being wound from the top downwardly to a point spaced from the bottom of the chamber, then extended directly downwardly to said bottom and tlien wound upwardly around the containers throughout the remainder of its length.

CARL E. L. LIPMAN. 

